|Magnet type||Alnico 2 (early are Alnico 2 to 5)|
|Voltage (RMS), V||127 mV at 7.715 kHz resonant frequency|
|Impedance, kΩ||319 kΩ at 7.715 kHz resonant frequency|
P.A.F. or just PAF is the world's second humbucker guitar pickup, invented by Seth Lover in 1955 as an engineer for Gibson and began use in mass production guitars in 1957. It is commonly mistaken for the first humbucker pickup due to Gibson's popularity and the earlier patent filing date. While the first humbucker pickup in use, and issued a patent, was actually the Gretsch Filter'Tron pickup prototypes, designed by Ray Butts in 1954 at the request of Chet Atkins for his Gretsch 6120 (1955 introduction)(Filter'Tron production also starting in 1957).
The strange name (PAF) of the pickup was not intentional. Gibson and Seth Lover first filed a patent on the design on June 22, 1955. After that, Gibson Les Pauls were equipped with these new pickups, with a sticker on a bottom plate of a pickup that said Patent Applied For. A patent was eventually issued on July 28, 1959. Since it took more than four years to get a patent number, the unnamed pickup had been dubbed "PAF" by many guitarists during the period the application was pending, and this name continued even after the patent had been issued.
PAF pickups can usually be identified by their look: they have two internal coil bobbins under a 1.5" x 2.75" metal cover with one bobbin having a row of six adjustable pole pieces, with the other bobbin having non-adjustable pole pieces. Standard PAF pickups had 5000 or so turns  of wire on a bobbin and a DC resistance of 7.5 kΩ (early pickups range from 7.5 kΩ to 9.0 kΩ).
The range of 1956-1961 is usually dubbed the era of early PAFs. These pickups were first used on lap steel guitars in 1956, on Les Paul Gold Top, and Les Paul Custom electric solid-bodied guitars in 1957. They replaced the out-dated P90 pickup(invented after WWII) and the best pickup Gibson offered the P90 "Staple" pickup, which was only offered on the Les Paul Custom and the company's highest end archtops.
These early PAFs tend to differ from each other significantly in terms of output level and tone - many factors are quoted as a reason for such difference:
- Gibson pickup winding machines were manually operated at that time and had no mechanisms to automatically cut the wire after a set number of turns. Thus the pickups had a different number of windings and that led to variation in the output and tone. For the same reason, the two coils within each pickup unit usually also have a slightly different number of turns.
- Gibson used Alnico magnets in PAFs, the same magnet as used in the P-90. Alnico has several different grades and different magnetic properties (grades 2, 3, 4 and 5 are usually used), and Gibson assigned them quite randomly until the end of the era of early PAFs. The most common of these was Alnico IV. British pickup designer Tim Mills of Bare Knuckle pickups had spoken with Seth Lover, who revealed that the most commonly used magnet was the Alnico IV. It has also been discovered from order sheets, that Gibson ordered many Alnico IV magnets.
- Original pickups manufactured in that time are over forty years old and thus their characteristic may have changed significantly over time, which includes the slow de-magnetization of the Alnico magnets, and also the warping of the bobbins(which changes the placement of the wire, changing the sound slightly).
Early pickups were wound with #42 plain enameled wire, this wire has a purple color, as opposed to later varieties(which were poly coated). During July 1961, Gibson standardized the PAF construction process, automatic stops were installed in the winders, which did not cause large differences in output between two pickups. The early '61 PAFs are almost exactly identical to the 1957-1960 PAFs. By mid to late '61 a new, smaller Alnico 5 magnetic plate became standard, which is referred to as a "short magnet". In about 1963, Gibson switched to polyurethane-coated wire to cut costs, changing the wire color from purple to red. In addition these pickups were also given a new sticker that had the "Patent No" written on it, as opposed to "Patent Applied For" About 1965-1968, automatic pickup winding machines came into use, thus making pickups that had a consistent number of turns and a fixed DC resistance. After about 1967, the original PAF design changed. These pickups are referred to as "Pre-T-tops". Gibson began to stamp the patent number on some PAF stickers after they obtained a patent (U.S. Patent 2,896,491) for the PAF pickups. Most humbuckers were labelled with U.S. Patent 2,737,842 until 1962 and the number shown on the pickups, which actually is a patent for a Gibson trapeze tailpiece bridge and not for a pickup at all. Both true PAFs and incorrect patent marked PAFs are fairly rare today and make an expensive vintage collectors item. By the early 70s Gibson began putting a T-shaped toolmark on their pickups' bobbins. This helped the workers make sure that the bobbin was facing the correct way during assembly. During the production of this pickup many original specifications changed, like the use of a wooden maple spacer (replaced by plastic), and the thickness of the magnet (got thinner). These pickups are referred to as "T-tops". Production of these pickups continued until the late 70s/early 80s.
By 1981, Gibson realized that there was a market and consumer demand for these older pickups. They assigned engineer Tim Shaw to research and create a re-issue of the older PAF pickups. Gibson at the time were now releasing Les Pauls that were built to somewhat vintage specifications for the first time (these guitars would later be called pre-historics, as they were the precursor to the Gibson Custom Shop re-issue line, which built to vintage specifications). Tim Shaw researched and tried to recreate the old toolmarks and other details that made these pickups what they were. Unfortunately, under the strict Norlin owners, many of his ideas were seen as too expensive and not cost effective. However Shaw was able to re tool the bobbin without the "T" that had been used throughout the past decade and re-introduce the correct square hole back into the bobbin, and more importantly use a thicker magnet which was the correct thickness to magnets used in PAFs. He also discovered that the wire used was enamel. Realizing that they used poly-coated wire, he tried to convince corporate that they needed the enamel coated wire. At the time however the enamel coated wire cost about 1 dollar more, and was not approved to be bought or used. He also found old sheets that explained the number of winds used, and even contacted the original designer Seth Lover and spoke to him about parts used on these pickups. Tim Shaw's efforts, even though not reaching the desired end goal he wanted, were a big leap forward in finding out information about these pickups. His efforts were considered by many to be the first in the long journey many would take in re-creating the PAF humbucking pickup.
Nowadays, the PAF is considered a vintage humbucker with relatively low output and soft, mellow tone. However, original Gibson PAFs are scarce and very expensive, so most major pickup manufacturers produce copies of original PAF design.
Notable pickups include:
- Seymour Duncan SH-55 Seth Lover Model. A modern pickup that reproduces Seth Lover's '55 prototype design in great detail: a nickel silver cover (not brass one), long bottom plate, plain #42 enamel wire, Alnico 2 magnets, wooden spacer, and black paper tape. Seth and Seymour were great friends, and Seth gave Seymour all of the original specs. In addition, Seymour owns Gibson's pickup winding machine from the '50s, and all SH-55's are wound on it.
- Seymour Duncan SH-1 '59 Model. A replica of late '50s PAFs, gives a slightly fatter sound, more known as a signature tone of famous blues/rock guitarists of the 1960s.
- Seymour Duncan Antiquity Humbucker (11014-01 and 11014-05). An as-close-as-possible replica of a late '50s PAF, complete with a patented aging technique.
- Seymour Duncan SH-5 Duncan Custom. This pickup is made quite differently compared to most PAF pickups (including use of a ceramic magnet instead of an Alnico one), but was designed to mimic a PAF pickup while offering higher output and compression.
- Kent Armstrong (son of Dan Armstrong) makes a variety of PAF models.
- Gibson "'57 Classic" Gibson's most regular take on the PAF. Not scatter wound, wax potted. Since the mid-'80s this is the standard pickup on most higher level guitars.
- Gibson Burstbucker. Gibson's newest take on the P.A.F. Scatter wound, not wax potted, these are the closest replicas Gibson makes. These pickups come stock on the Historic line of Reissue Les Pauls.
- SKATTERBRANE Earthbrane. Scatter wound PAF pickup. Featuring plain alkyd enamel 42awg magnet wire, rough cast magnets, butyrate bobbins and maple spacer. Also includes true German silver covers and backing plates.
- DiMarzio PAF (DP103). One of the earliest PAF replicas, wax potted with Alnico 5 magnets, 4-conductor cable for split and series/parallel wiring.
- DiMarzio PAF Classic Bridge (DP195) and Neck (DP194). PAF pickups with pre-installed covers, wax-dipped twice (before cover installation and after).
- DiMarzio Virtual Hot PAF (DP214), Virtual PAF Bridge (DP197), Virtual PAF Neck (DP196). Pickups built with patented Virtual Vintage technology that gives a more balanced pickup characteristic.
- Bare Knuckle Pickups The Mule. An accurate scatter wound PAF replica: The Mule uses a nickel-silver baseplate and cover, #42 AWG plain enamel wire, unpolished Alnico 4 magnets, maple spacer and butyrate bobbins.
- Throbak Electronics MXV Maximum Vintage Series PAF. Throbak manufactures their vintage style PAF pickups by replicating, as closely as possible, the process and materials used in producing the original PAFs. Their coil windings are done on the same types of machines (Leesona 102), and in some cases the original machines (the Gibson made and designed Slug 101), that produced the original 1950's PAFs in the Gibson factory in Kalamazoo.
- Durrant pickups Crackerjack is a modern representation of the PAF. Using Vintage materials and specs but offering a more modern look.
Patents related to PAF pickup:
- By Rich Kienzie, "Riffs, Amps, and Butts", Guitar Player Magazine, March 1990, P.14
- Joseph Raymond Butts, U.S. Patent 2892371 , issued June 22nd, 1959